Family Hylobatidae, also known as gibbons, are small, slender apes found in the tropical and subtropical rainforests of Southeast Asia. There are 18 species of gibbons that are commonly classified into four genera: Hylobates, Hoolock, Nomascus, and Symphalangus. These arboreal primates are known for their distinctive vocalizations that enable them to communicate with each other across the forest canopy. Gibbons are also known for their incredible agility, with the ability to swing and leap through the trees with ease. Synonyms for Family Hylobatidae include the lesser apes, small apes, and tree apes. Despite their small size, gibbons play an important role in maintaining the biodiversity of rainforest ecosystems.